Explosion and fire release ventilator



May 11, 1965 K. s. VON POEDEROYEN ETAL 3,132,581

EXPLOSION AND FIRE RELEASE VENTILATOR Filed Dec. 3, 1962 2 Sheets-Sheet 1 IN VEN TOR.

KARL S. VON POEDEROYEN BY FULWIDER, MTTON-p RIEBER, LEE 8- UTECHT ATTORNEYS May 11, 1 K. s. VON POEDEROYEN ETAL EXPLOSION AND FIRE RELEASE VENTILATOR 2 Sheets-Sheet 2 Filed Dec. 3, 1962 Rm mRN O m um p 5 NR :I-AVUM w m m Y ms FIG.4

RIEBER,- LEE 8- UTECHT ATTORNEYS United States Patent EXPLOSION AND FIRE RELEASE VENTILATOR Karl S. Von Poederoyen, Van Nuys, and Wolfram G.

Korif, Granada Hills, Calif., assignors to Western Engineering 8c Mfg. C0,, Venice, Calif., a corporation of California Filed Dec. 3, 1962, Ser. No. 241,610 13 Claims. (Cl. 98-86) The present invention relates to a ventilator and more particularly to a ventilator which is adapted for both manual and automatic actuation to open and vent the interior of a building, particularly in the event of a fire or explosion.

It is extremely important to vent the noxious gases and accumulations of pressure which occur during a building fire. Concentrations of smoke and fumes complicate the fire fighters task and frequently contribute to the intensity of the fire. Moreover, failure to immediately vent the destructive force of an explosion can and often does structurally damage the building because of the inability of the building walls and roof to withstand the tremendous forces exerted against them from the sudden build-up of internal building pressures during an explosion.

Accordingly, it is an object of the present invention to provide a ventilator which is adapted to be actuated either manually or automatically to vent through an associated opening the products of a fire or an explosion within a building.

Another object of the invention is to provide a ventilator of the aforementioned character which includes a means for holding the door of the ventilator open after the initial shock Wave of an explosion has subsided. This prevents the development in the building of highly dangerous negative pressures immediately subsequent to the explosion, and also precludes subsequent, successive accumulations of explosive gases or vapors.

A further object of the invention is the provision of a ventilator of the aforementioned character which includes a door pivotally mounted to a base which is positioned adjacent the opening in the building through which the gases are to be vented. The door is connected to the base by means of a pair of telescoping hinge arms which are extensible and retractable to orient the door in an open position and in a closed position, respectively, the telescoping hinge arms being constrained against extension by gravity and by the working friction of the ventilator components. The arms are driven into an extended position by a spring-biased thrust element which is normally disengageably secured to the base by -a release arm, the bias means being operative to extend the hinge arms relative to each other upon disengagement of the thrust element. The telescoping hinge arms encompass the bias means so that it is not exposed upon actuation of the ventilator, thereby avoiding the possibility of accidental injury to an operator. In addition, although it is necessary to operate the bias means to positively drive the door to an open position, the hinge arm connected to the door is freely slidable relative to the other hinge arm and the thrust element, except for working friction, so that when the door is subjected to high internal building pressures it is movable to an open position under the impetus of such pressures. Moreover, once the door approaches its open position the manner of connection of the release arm to the thrust element is such that the angle of orientation of the partially extended hinge arms automatically effects disengagement of the release arm from the thrust element whereby the door is maintained in its open position by the bias means subsequent to the release of the thrust element. This fixes the door in its open position to continuously vent the interior of the building until the door is closed manually.

Another object of the invention is to provide a ventilator of the aforementioned character in which the hinge arms, the release arm, and the actuating mechanisms therefor occupy a minimum space to permit fire fighters to have access to the building through the opening which is being vented.

A further object of the invention is the provision of a ventilator of the aforementioned character in which the release arm which is operative to initiate opening of the door is itself operated by an actuating mechanism which is spring-loaded and connected to the release arm through a fusible link. When the building temperatures reach a predetermined level, the link is severed and the preloaded actuating mechanism operates the release arm to disengage the thrust element and permit movement of the door to its open position. In this regard, it is another feature of the invention that the ventilator may be reset for subsequent operation by merely replacing the fusible link and closing the door to re-engage the thrust element with the release arm to thereby lock the door in its closed position over the opening in the building.

A further object of the invention is the provision of a ventilator of the aforementioned character in which the ventilator door may be opened manually from outside the building by pulling upon a handle or the like attached to the door, or from inside the building by pulling a chain or the like attached to one end of the release arm, thereby disengaging the release arm from the thrust element.

Another object of the invention is to provide a ventilator of the aforementioned character which is simple to operate, easy to maintain, and relatively inexpensive to manufacture and install.

These and other objects and advantages of the present invention will become apparent from the following detailed description, when taken in conjunction with the appended drawings, wherein:

FIGURE 1 is a perspective view of the ventilator of the present invention, particularly illustrating a pair of open ventilator doors which when closed form a peaked, weather-resistant structure not subject to high snow loads;

FIGURE 2 is a fragmentary elevational view of the present ventilator, illustrating one of the ventilator doors being driven to its open position under the impetus of an explosion or the like;

FIGURE 3 is a view similar to FIGURE 2, but illustrating the ventilator in its closed position, a portion thereof being illustrated in cross-section;

FIGURE 4 is a View similar to FIGURE 2, but illustrating the ventilator in its open position; and

FIGURE 5 is a view taken along the line 55 of FIG- URE 4.

Referring now to the drawings, and particularly to FIGURE 2 thereof, there is illustrated a ventilator 10 according to the present invention, which includes a supporting structure or base 12 adapted to be positioned or mounted adjacent a rectangular curb 14 which defines the roof opening of the building from which gases are to be vented. The base 12 pivotally mounts a pair of areaasr 3 doors 16 at their inner margins so that the doors 16 may be actuated to open positions by two pairs of hinge arms 18 and 20 connected between the doors 16 and the base 12.

Each arm 18 is pivotally mounted to a door 16 and is slidably and telescopically receivable within an arm 20 so that the arms 18 and 20 are freely extensible and retractable to orient the associated door 16 in open and closed positions, respectively. Each arm 20 includes an integral mounting bracket 21 by which the arm 20 is pivotally secured to the base 12.

Arms 18 and 26 are driven into their extended positions by a thrust element 22 acting under the bias of a spring 24 which is interposed between the arm 20 and the thrust element 22. The element 22 is normally disengageably secured to the base 12 by a release means or arm 26, one for each element 22, which can he disengaged to free the element 22 for outward movement under the bias of the spring 24. This outward movement is preferably transmitted directly to the structure of the door 16 to eifect the desired extension of the arms 18 and 2t) and opening of the door 16.

The base 12 is preferably made of corrosion-resistant sheet metal and includes parallel, elongated sides 23 rigidly secured or welded at their extremities to a pair of ends 39 whose upper margins converge inwardly from the sides 2% to form a generally triangular transverse section for supporting the doors 16 in their closed positions. The sides 28 and ends 30 preferably are fitted upon the curb 14 in weatherproof fashion, and for this purpose include flashing constituted by a horizontally oriented shelf portion 32 which rests upon the top of the curb 14, and an integral depending skirt section 34 which depends adjacent the outer side of the curb 14. The portion 32 and section 34 extend about the complete perimeter of the ventilator 16, any suitable fasteners (not shown) being used for secureinent thereof to the curb 14 to hold the ventilator 10 in position adjacent the roof opening.

The base 12 also includes an elongated, channel-shaped brace 36 extending between and connected to the apices of the triangularly-shaped ends 30 to structurally rigidity the ends 30 for the support of the doors 16. Another elongated channel brace 38 extends transversely of the sides 28 of the base 12, being secured thereto for strengthening the sides 28 and for supporting certain components of the ventilator it including the inner or lower extremities of the arms 29, as will be described more particularly hereinafter.

The pivotal mounting of the rectangular doors 16 to the base 12 may be provided by any suitable hinge means (not shown) eifective to firmly and pivotally hold the doors 16 in position for actuation by the hinge arms 18 and 26. In this regard, it will be apparent that only one hinged door may be utilized, if desired, the present description of a ventilator 1t] employing two doors 16 merely being exemplary. The door opening and closing apparatus operates equally well upon either a single door or a pair of doors 16.

Each door 16, as best illustrated in FIGURES 1 and 3 through 5, is extensible to an open position, as shown in FIGURE 4, and retractable to a closed position, as illustrated in FEGURE 3, by the hinge arms 18 and 26. Both of the hinge arms 18 and 20 are elongated and preferably cylindrical in form to fit together in slidable, telescoping fashion with the arm 18 carried within the arm 20.

The arm 18 includes an annular boss 40 at its lower extremity for properly orienting the lower end of the arm 13 within the arm 20 during its slidable movement. The extent of telescoping retraction of the arm 18 relative to the arm 20 is limited by engagement between the door 16 and brace 36. An annular end plate 42 is integral with the lower extremity of the arm 20. Relative extension of the arms 18 and 20 is limited by engagement of the boss 40 with a split ring 44 comprising two sectors defining a space 43 and secured within the upper extremity of the arm 20 by a pair of bolts 46 or similar fasteners, an annular butler ring 47 being interposed therebetween to cushion any opening shock. The central opening in the annular ring 44 is large enough to slidably pass and guide the arm 18 during its extension and retraction relative to the arm 20, and the space 43 allows the pin 58 to pass by the ring 44.

The arm 20 also includes an elongated tubular guide 48 constituting an upward extension of the end plate 42, the guide 48 being coaxial with the cylindrical exterior portion of the arm 20. The guide 48 slidably and telescopically receives a tubular shank 50 of the thrust element 22 in addition, a cylindrical piston 52 is slidably fitted over the upper extremity of the shank 50 in encompassing relationship.

The piston 52 is secured to the shank 54) by a transverse pin 53, and has a diameter approximating the internal diameter of the arm 20 so as to be longitudinally slidable therewithin. The bias means or compression spring 24 is coaxial with the shank 5t) and engages the end plate 42 at its lower extremity and the underside of the piston 52 at its upper extremity whereby the thrust element 22 is constantly biased toward the door 16 by the spring 24.

The lower extremity of the thrust element 22 is normally disen-gageably connected to the release arm 26 by engagement between a hook portion 54 of the release arm 26 and a transverse roller pin 56 which is rotatably carried by the thrust element 22 at the lower extremity of the shank 50, the portion 54 extending upwardly through a suitable slot 57 provided in the transverse brace 38. As will be apparent from a comparison of the positions of the hook portion 54 and the thrust element 22 in the closed positions of the doors 16, as best illustrated in FIGURE 3, and the corresponding positions of these components in the open positions of the doors 16, as best illustrated in FIGURE 4, the hook portion 54 firmly engages the roller pin 56 to maintain the thrust element 22 in retracted position adjacent the base 12 when the door 16 is in its closed position. However, when the door 16 approaches its open position, as seen in FIGURE 4, the angle of inclination of the thrust element 22 relative to the base 12 is reduced or more acute, permitting the roller pin 56 to roll out of engagement with the detent of the hook portion 54.

With this arrangement, whenever the door 16 is manually pulled open from the exterior of the building, as by grasping a suitable exterior handle (not shown), the thrust element 22 is released by the release arm 26 upon approach of the door to its open position. The bias of the spring 24 then drives the thrust element 22 outwardly to extend the hinge arm 18, thereby maintaining the door 16 in its open position. Likewise, upon automatic actuation of the door 16 toward an open position, as will subsequently be described, the release arm 26 disengages the roller pin 56 in similar fashion releasing the thrust element 22 so that the door 16 is biased to its open position by the spring 24 acting against the thrust element 22.

The outer or upper extremity of the hinge arm 18 is pivotally secured to the door 16 by a transversely disposed pin 58 carried by an elongated adjustment link 60 which is arranged parallel to the plane of the door 16. One extremity of the adjustment link 60 includes a transversely oriented tab 62 having a central opening therein to accommodate an adjustment bolt which is rigidly secured to the door 16. A nut 66 threaded upon the end of the bolt 64 is engaged by one end of a compression spring 68 whose other extremity engages the tab 62 to bias the adjustment link 60 and the door 16 closer together, there being sufficien-t clearance between the shank of the bolt 64 and the margin of the opening in the tab 62 to permit relative movement therebetween. The opposite extremity of the adjustment link 60 is pivotally secured to a hinge arm 70 which is fixed to the door 16. Consequently, when the thrust element 22 is engaged by the release arm 26, rotation of the nut 66 adjusts the position of the door 16 relative to the thrust element 22 to take up undesirable play or back-lash the-rebetween in the closed position of the door 16.

The hinge arm 70 to which the lower extremity of the adjustment link 60 is mounted is itself pivotally secured to the base 12 by means of a hinge bracket 72 integral with the base 12, thereby pivotally supporting the midportion of the door 16 upon the base 12.

The door 16 is movable to an open position by the thrust element 22 through engagement between the pin 58 and a portion 74 of the piston 52. The piston portion 74- includes a transversely oriented slot or detent 76 which is adapted to receive and engage the transversely oriented pin 58. With this arrangement, extension of the thrust element 22 relative to the arm 26 also extends the arm 1-8 and the door 16 pivotally attached thereto.

Since the arm 18 is freely movable relative to the arm 20, the door 16 can be moved to an open position regardless of engagement of the thrust element 22 by the hinge arm 26, permitting manual opening of the doors 16 from either the inside or the outside of the building. Moreover, in the event of an explosion within the building, the pressures generated acting upon the undersurface of the closed doors 16 move them to open positions with the hinge arm 18 sliding relative to the thrust element 22 and the hinge arm 20, as best illustrated in FIGURE 1. When the door .16 approaches its open position, the axis of the thrust element 22 tips downwardly, and the arm 26 is constrained against moving in the same direction so that the roller pin 56 moves outwardly of and disengages the hook 54, releasing the thrust element 22 for engagement with the pin 58, as previously described, whereby the bias of the spring 24 maintains the door 16 in its open position.

Since the thrust element 22 is constrained solely by the release arm 26, it will be apparent that pivotal movement of the arm 26 by an operator within the building or otherwise will be elfective to open the doors 16. For this purpose, the release arm 26 is pivotally mounted to the brace 38 of the base 12 by a pin 78, and the extremity of the release arm 26 opposite the hook portion 54 is provided with an aperture for receiving a chain 80 extending downwardly into the building. tPulling upon the chain 80 pivots the arm 26 and disengages the hook portion 54 thereof from the roller pin 56. Upon release of the chain 86, the arm 26 is biased by a tension spring 82 to a position for eifecting engagement between the hook portion 54 and the roller pin 56 when roller pin 56 is returned to its engaging position. The spring 82 is suitably connected atone extremity to the release arm 26 and is connected at its opposite extremity to the longitudinal brace 36 of the bae 12 by a chain 82.

The release arms 26 for both of the doors 16 are also simultaneously pivoted for release of the thrust elements 22 by an actuator bar 84 Which is arranged beneath the lateral brace 38 in parallel relationship therewith and adjacent the arms 26. The opposite extremities of the actuator bar 84- are located adjacent the extremities of the two release arms 26 so that downward movement of the bar 84 simultaneously pivots both arms 26 to release their associated thrust elements 22.

The actuator bar 84 is moved downwardly upon actuation of a bias means or compression spring 86 whose upper extremity engages the underside of the transverse brace 38 and whose lower extremity engages an annular washer 88 forming an integral part of a tubular sleeve 90 which encloses the spring 86, and which is rigidly secured to the actuator bar S4. The bar 84 is normally held in position adjacent the underside of the transverse brace 33, against the bias of the spring 86, by a bolt 92 having a head 94 which engages the underside of the annular washer 88. The bolt 92 includes a shank 96 integral with the head 94 and extending upwardly through the spring 86 and a suitable opening provided therefor in the transverse brace 38. The shank 96 is slidable in the opening, and includes a transverse stop washer 93 at its upper extremity to limit the extent of travel of the shank 96 upon release of the bolt 92.

The bolt 92 is held in the position illustrated in FIG- URE 3 by a fusible link 100 and chain sections 102 and 104 secured between the upper extremity of the shank 96 and the longitudinal brace 36. When the temperature surrounding the link 100 attains a predetermined level indicating a fire in the building, such as 212 F., the link 1% fuses or melts, severing the connection between the bolt 92 and the longitudinal brace 36. The bias of the spring 86 then drives the sleeve and its associated actuator bar 86 downwardly, pivoting both release arms 26 and releasing the hook portions 54 thereof from their associated roller pins 56.

Thus, the doors 16 are adapted to be actuated either manually or automatically to vent the products of a fire or an explosion Within the building. The doors 16 are maintained in their open positions by the bias of the springs 24 acting against the thrust elements 22 subsequent to disengagement between the roller pins 56 and the hook portions 54, thereby permitting continued venting of the building subsequent to an explosion or fire. Moreover, since the springs 24- fior biasing the doors 16 open are completely enclosed, nearby persons are shielded from possible injury upon actuation thereof.

The actuating apparatus of the ventilator 10 occupies a minimum space in the building opening to be vented, thereby affording ample access to the building through the opening. Resetting of the actuating apparatus or mechanism is relatively simple, merely requiring recompression of the spring 86 and replacement of the fusible link 16%.

Various modifications and changes may be made with regard to the foregoing detailed description without departing from the spirit of the invention or the scope of the following claims.

We claim:

1. A ventilator comprising:

a base adapted for mounting adjacent an opening in a building;

a door mounted to said base for pivotal movement between a closed position over said opening and an open position away from said opening;

an elongated first hinge arm;

an elongated second hinge arm longitudinally and coaxially extendible and retractable relative to said first hinge arm;

an elongated thrust element carried by one of said hinge arms for longitudinal, coaxial extension and retraction relative to said hinge arms to open and close said door, one of said first and second hinge arms being pivotally connected to said door, and the other of said first and second hinge arms being pivotally con nected to said base;

release means normally disengageably connected to said thrust element when said door is in said closed position and constraining said thrust element against extension relative to said first hinge arm;

bias means interposed between said first hinge arm and said thrust element and tending to urge said thrust element into extended relationship to move said door toward said open position, said second hinge arm being freely longitudinally extendible independently of said thrust element and said first hinge arm upon movement of said door toward said open position and during engagement between said thrust element and said release means;

and means normally maintaining said release means in engagement with said thrust element and operable to disengage said release means from said thrust element whereby said thrust element is extendible under the bias of said bias means to move said door into said open position.

2. A ventilator comprising:

a base adapted for mounting adjacent an opening in a building;

a door mounted to said base for pivotal movement between a closed position over said opening and an open position away from said opening;

an elongated first hinge arm;

an elongated second hinge arm longitudinally and coaxially extendible and retractable relative to said first hinge arm;

an elongated thrust element telescopically earriedby one of said hinge arms for longitudinal, coaxial extension and retraction relative to said hinge arms to open and close said door, one of said first and second hinge arms being pivotally connected to said door, and the other of said first and second hinge arms being pivotally connected to said base;

release means normally disengageably connected to said thrust element when said door is in said closed position and constraining said thrust element against extension relative to said first hinge arm;

bias means interposed between said first hinge arm and said thrust element and tending to urge said thrust element into extended relationship to move said door toward said open position, said second hinge arm being freely longitudinally extendible independently of said thrust element and said first hinge arm upon movement of said door toward said open position and during engagement between said thrust element and said release means;

and means normally maintaining said release means in engagement with said thrust element and including a link severable upon exposure to a predetermined temperature to operate said release means for disengagement from said thrust element whereby said thrust element is extendible under the bias of said bias means to move said door into said open position.

3. A ventilator comprising:

a base adapted for mounting adjacent an opening in a building;

a door mounted to said base for pivotal movement between a closed position over said opening and an open position away from said opening;

an elongated first hinge arm;

an elongated second hinge arm longitudinally and co axially extendible and retractable relative to said first hinge arm;

an elongated thrust element carried by one of said hinge arms for longitudinal, coaxial extension and retraction relative to said hinge arms to open and close said door, one of said first and second hinge arms being pivotally connected to said door and the other of said first and second hinge arms being pivotally connected to said base;

release means normally disengageably connected to said thrust element when said door is in said closed position and constraining said thrust element against extension relative to said first hinge arm; bias means interposed between said first hinge arm and said thrust element and tending to urge said thrust element into extended relationship to move said door toward said open position, said second hinge arm being freely longitudinally extendible independently of said thrust element and said first hinge arm upon iovement of said door. toward said open position and during engagement between said thrust element and said release means; and. means normally maintaining said release means in engagement with said thrust element and including a link severable upon exposure to a predetermined temperature, an actuator engaged with said release means and movable to disengage said release means from said thrust element, flexible means connecting said actuator and said link and preloading said actuator 0 whereby upon severance of said link said actuator is moved.

4. A ventilator comprising:

a base adapted for mounting adjacent an opening in a building;

a door mounted to said base for pivotal movement between a closed position over. said opening and an open position away from said opening;

an elongated first hinge arm;

an elongated second hinge arm longitudinally and coaxially extendible and retractable relative to said first hinge arm;

an elongated thrust element carried by one of said hinge arms for longitudinal, coaxial extension and retraction relative to said hinge arms to open and close said door, one of said first and second hinge arms being pivotally connected to said door and the other of said first and second hinge arms being pivotally connected to said base;

release means normally disengageably connected to said thrust element when said door is in said closed position and constraining said thrust element against extension relative to said first hinge arm;

bias means interposed between said first hinge arm and said thrust element and tending to urge said thrust element into extended relationship to move said door toward said open position, said second hinge arm being freely longitudinally extendible independently of said thrust element and said first hinge arm upon movement of said door toward said open position and during engagement between said thrust element and said release means;

and means normally maintaining said release means in engagement with said thrust element and including a pull member connected to said release means and operable to pull upon and disengage said release means from said thrust element whereby said thrust element is extendible under the bias of said bias means to move said door into said open position.

5. A ventilator comprising:

a base adapted for mounting adjacent an opening in a building;

a door mounted to said base for pivotal movement between a closed position covering said opening and an open position uncovering said opening;

an elongated first hinge arm;

an elongated second hinge arm carried by said first hinge arm for longitudinal, coaxial movement relative to said first hinge arm;

an elongated thrust element carried by at least one of said hinge arms for longitudinal, coaxial movement relative thereto, said first hinge arm being pivotally connected to said base, and said second hinge arm being pivotally connected to said door;

a release arm pivotally connected to said base and normally disengageably connected to said thrust element when said door is in said closed position to constrain said thrust element against longitudinal movement;

bias means interposed between said first hinge arm and said thrust element to urge said thrust element and said first hinge arm into extended relationship to move said door toward said open position, said second hinge arm being freely longitudinally extendible independently of said thrust element and said first hinge arm upon movement of said door toward said open position and during engagement between said thrust element and said release means;

and means normally maintaining said release means in engagement with said thrust element and operable to disengage said release means from said thrust element whereby said thrust element is extendible under the bias of said bias means to move said door into said open position.

6. A ventilator comprising:

a base adapted for mounting adjacent an opening in a building;

a door mounted to said base for pivotal movement between a closed posit-ion over said opening and an open position away from said opening;

an elongated first hinge arm;

an elongated second hinge arm carried by said first hinge arm for longitudinal, slidable, coaxial extension and retraction relative to said first hinge a-rm;

an elongated thrust element carried by one of said hinge arms for longitudinal, slidable, coaxial extension and retraction relative to said hinge arms and including a pin at one extremity, one of said first and second hinge arms being pivotally connected to said door and the other of said first and second hinge arms being pivotally connected to said base;

a release arm pivotally mounted to said base and having a hook portion at one extremity disengageably fitted upon said pin when said door is in said closed position to constrain said thrust element against extension;

bias means interposed between said first hinge arm and said thrust element and tending to urge said thrust element into extended relationship to move said door toward said open position, said second hinge arm being freely longitudinally extendible independently of said thrust element and said first hinge arm upon movement of said door toward said open position and during engagement between said thrust element and said release arm;

and means normally maintaining said hook portion in engagement with said pin and operable to effect disengagement therebetween whereby said thrust element is extendible under the bias of said bias means to move said door into said open position.

7. A ventilator comprising:

a base adapted for mounting adjacent an opening in a building;

a door mounted to said base for pivotal movement between a closed position over said opening and an open position away from said opening;

an elongated first hinge arm;

an elongated second hinge arm telescopically carried by said first hinge arm for longitudinal extension and retraction relative to said .fi-rst hinge arm;

an elongated thrust element telescopically carried by said second hinge arm for longitudinal extension relative thereto to open and close said door, said second hinge arm being pivotally connected to said door and said first hinge arm being pivotally connected to said base;

release means normally disengageably connected to said thrust element when said door is in said closed position and constraining said thrust element against extension relative to said first hinge arm;

bias means interposed between said first hinge arm and said thrust element to urge said thrust element and said first hinge arm into extended relationship to move said door toward said open position, said second hinge arm being freely longitudinally extendible independently of said thrust element and said first hinge arm upon movement of said door toward said open position and during engagement between said thrust element and said release means;

and means normally maintaining said release means in engagement with said thrust element and operable to disengage said release means from said thrust element whereby said thrust element is extendible under the bias of said bias means to move said door into said open position.

8. A ventilator comprising:

a base adapted for mounting adjacent an opening in a building;

a door mounted to said base for pivotal movement between a closed position over said opening and an open position away from said opening;

an elongated first hinge arm;

an elongated second hinge arm carried by said first hinge arm for longitudinal, coaxial extension and retraction relative to said first hinge arm;

an elongated thrust element carried by said second hinge arm for longitudinal extension relative thereto to open and close said door, said first hinge arm being pivot-ally connected to said base;

an elongated adjustment link pivotally connected to said door at one extremity;

adjustment means connecting the opposite extremity of said adjustment link to said door to adjust the distance therebetween, said second hinge arm being pivotally connected to said adjustment link intermediate the extremities thereof for adjustment of the longitudinal position of said second hinge arm;

release means normally disengageably connected to said thrust element when said door is in said closed position and constraining said thrust element against extension relative to said first hinge arm;

bias means interposed between said first hinge arm and said thrust element and tending to urge said thrust element into extended relationship to move said door toward said open position, said second hinge arm being freely longitudinally extendible independently of said thrust element and said first hinge arm upon movement of said door toward said open position and during engagement between said thrust element and said release means;

and means normally maintaining said release means in engagement with said thrust element and operable to disengage said release means whereby said thrust element is extendible under the bias of said bias means to move said door into said open position.

9. A ventilator comprising:

a base adapted for mounting adjacent an opening in a building;

a door mounted to said base for pivotal movement between a closed position over said opening and an open position away from said opening;

an elongated first hinge arm;

an elongated second hinge arm carried by said first hinge arm for longitudinal, coaxial extension and retraction relative to said first binge arm;

an elongated thrust element carried by said second hinge arm for longitudinal extension relative thereto to open and close said door, said first hinge arm being pivotally connected to said base;

an elongated adjustment link pivotally connected to said door at one extremity;

adjustment means connecting the opposite extremity of said adjustment link to said door to adjust the distance therebetween, and including a pin by which said second hinge arm is pivotally connectedrto said adjustment link intermediate the extremities thereof for adjustment of the longitudinal position of said second hinge arm, said thrust element being engageable with said pin in the closed position of said door;

release means normally disengageably connected to said thrust element when said door is in said closed position and constraining said thrust element against extension relative to said first hinge arm;

and bias means interposed between said first hinge arm and said thrust element and tending to urge said thrust element against said pin to force said hinge arms into extended relationship to move said door toward said open position, said second hinge arm being freely longitudinally extendible independently of said thrust element and said first hinge arm upon movement of said door toward said open position and during engagement between said thrust element and said release means;

and means normally maintaining said release means in engagement with said thrust element and operable to disengage said release means from said thrust element whereby said thrust element is biased against said pin to extend said hinge arms to move said door into said open position.

10. A ventilator comprising:

a base adapted for mounting adjacent an opening in a building;

a door mounted to said base for pivotal movement between a closed position over said opening and an open position away from said opening;

an elongated first hinge arm;

an elongated second hinge arm, carried by said first hinge arm for longitudinal, coaxial extension and retraction relative to said first hinge arm;

an elongated thrust element carried by said second hinge arm for longitudinal extension relative thereto to open and close said door, said thrust element including a rotatable pin, said second hinge arm being pivotally connected to said door and said first hinge arm being pivotally connected to said base;

a release arm having a hook portion normally disengageably connected to said pin of said thrust element when said door is in said closed position and constraining said thrust element against extension relative to said first hinge arm;

bias means interposed between said first hinge arm and said thrust element and tending to urge said hinge arms into extended relationship to move said door toward said open position, said second hinge arm being freely longitudinally extendible independently of said thrust element and said first hinge arm upon movement of said door toward said open position and during engagement between said hook portion and said pin, said portion being configured to roll ofi said pin upon said door approaching said open position whereby said thrust element is movable under the bias of said bias means to maintain said door in said open position;

and means normally maintaining said hook portion in engagement with said pin and operable to disengage said hook portion from said pin whereby said thrust element moves said door toward said open position.

11. A ventilator comprising:

a base adapted for mounting adjacent an opening in a building;

a pair of doors mounted to opposite sides of said base for pivotal movement between a closed position over said opening and an open position away from said opening;

a pair of elongated first hinge arms;

a pair of elongated second hinge arms carried, respectively, by said pair of first hinge arms for longitudinal, coaxial extension and retraction relative to said pair of first hinge arms;

a pair of elongated thrust elements carried, respectively, by said second pair of hinge arms for longitudinal extension relative thereto to open and close said pair of doors, said second hinge arms being pivotally connected to said doors and said first hinge arms being pivotally connected to said base;

a pair of release arms pivotally mounted to said base and normally disengageably connected to said thrust elements when said doors are in said closed position, and constraining said thrust elements against extension relative to said first hinge arms;

a pair of bias means interposed between said first hinge arms and said thrust elements and tending to urge said thrust elements into extended relationship to move said doors toward said open position, said second hinge arms being freely longitudinally slidable independently of said thrust elements and said first hinge arm upon movement of said doors toward said open position and during engagement between said thrust elements and said release means;

and means normally maintaining said release arms in engagement with said thrust elements and operable to pivot and disengage said release arms from said thrust elements whereby said thrust elements are extendible under the bias of said pair of bias means to move said doors into said open position, said means including an actuator bar movable to simultaneously engage and pivot said release arms, second bias means tending to move said actuator bar, and flexible means normally constraining said actuator bar against movement and severable to permit movement of said actuator bar.

12. A ventilator comprising:

a base adapted for mounting adjacent an opening in a building;

a pair of doors mounted to opposite sides of said base for pivotal movement between a closed position over said opening and an open position away from said opening;

a pair of elongated first hinge arms;

a pair of elongated second hinge arms carried, respectively, by said pair of first hinge arms for longitudinal, coaxial extension and retraction relative to said pair of first hinge arms;

a pair of elongated thrust elements carried, respectively, by said second pair of hinge arms for longitudinal extension relative thereto to open and close said pair of doors, said second hinge arms being pivotally connected to said doors and said first hinge arms being pivotally connected to said base;

a pair of release arms pivotally mounted to said base and normally disengageably connected to said thrust elements when said doors are in said closed position, and constraining said thrust elements against extension relative to said first hinge arms;

a pair of bias means interposed between said first hinge arms and said thrust elements and tending to urge said thrust elements into extended relationship to move said doors toward said open position, said second hinge arms being freely longitudinally slidable independently of said thrust elements and said first hinge arms upon movement of said doors toward said open position and during engagement between said thrust elements and said release arms;

and means normally maintaining said release arms in engagement with said thrust elements and operable to pivot and disengage said release arms from said thrust elements whereby said thrust elements are extendible under the bias of said pair of bias means to move said doors into said open position, said means including an actuator bar movable to simultaneously engage and pivot said release arms, second bias means tending to move said actuator bar, and flexible means normally constraining said actuator bar against movement and including a link fusible at an elevated temperature to sever said flexible means to permit movement of said actuator bar.

13. A ventilator comprising:

a base adapted for mounting adjacent an opening in a building;

a door mounted to said base for pivotal movement between a closed position over said opening and an open position away from said opening;

an elongated first hinge arm;

an elongated second hingearm extendible and retractable relative to said first hinge arm;

an elongated thrust element movable upon release to open said door, one of said first and second hinge arms being pivotally connected to said door and the other of said first and second hinge means being pivotally connected to said base whereby relative extension of said hinge arms occurs upon movement of said door to said open position;

release means normally disengageably connected to said thrust element when said door is in said closed posi- 13 tion and constraining said thrust element against movement; bias means operative upon said thrust element and tending to move said thrust element to open said door, said hinge arms being freely extensible relative to each other independently of said thrust element' upon movement of said door toward said open position and during engagement between said thrust element and said release means;

and means normally maintaining said release means in engagement with said thrust element and operable to disengage said release means from said thrust element whereby said thrust element is movable to move said door toward said open posit-ion.

References Cited by the Examiner UNITED STATES PATENTS ROBERT A. OLEARY, Primary Examiner. 

2. A VENTILATOR COMPRISING: A BASE ADAPTED FOR MOUNTING ADJACENT AN OPENING IN A BUILDING; A DOOR MOUNTED TO SAID BASE FOR PIVOTAL MOVEMENT BETWEEN A CLOSED POSITION OVER SAID OPENING AND AN OPEN POSITION AWAY FROM SAID OPENING; AN ELONGATED FIRST HINGE ARM; AN ELONGATED SECOND HINGE ARM LONGITUDINALLY AND COAXIALLY EXTENDIBLE AND RETRACTABLE RELATIVE TO SAID FIRST HINGE ARM; AND ELONGATED THRUST ELEMENT TELESCOPICALLY CARRIED BY ONE OF SAID HINGE ARMS FOR LONGITUDINAL, COAXIAL EXTENSION AND RETRACTION RELATIVE TO SAID HINGE ARMS TO OPEN AND CLOSE SAID DOOR, ONE OF SAID FIRST AND SECOND HINGE ARMS BEING PIVOTALLY CONNECTED TO SAID DOOR, AND THE OTHER OF SAID FIRST AND SECOND HINGE ARMS BEING PIVOTALLY CONNECTED TO SAID BASE; RELEASE MEANS NORMALLY DISENGAGEABLY CONNECTED TO SAID THRUST ELEMENT WHEN SAID DOOR IS IN SAID CLOSED POSITION AND CONSTRAINING SAID THRUST ELEMENT AGAINST EXTENSION RELATIVE TO SAID FIRST HINGE ARM; BIAS MEANS INTERPOSED BETWEEN SAID FIRST HINGE ARM AND SAID THRUST ELEMENT AND TENDING TO URGE SAID THRUST ELEMENT INTO EXTENDED RELATIONSHIP TO MOVE SAID DOOR TOWARD SAID OPEN POSITION, SAID SECOND HINGE ARM BEING FREELY LONGITUDINALLY EXTENDIBLE INDEPENDENTLY OF SAID THRUST ELEMENT AND SAID FIRST HINGE ARM UPON MOVEMENT OF SAID DOOR TOWARD SAID OPEN POSITION AND DURING ENGAGEMENT BETWEEN SAID THRUST ELEMENT AND SAID RELEASE MEANS; AND MEANS NORMALLY MAINTAINING SAID RELEASE MEANS IN ENGAGEMENT WITH SAID THRUST ELEMENT AND INCLUDING A LINK SEVERABLE UPON EXPOSURE TO A PREDETERMINED TEMPERATURE TO OPERATE SAID RELEASE MEANS FOR DISENGAGEMENT FROM SAID THRUST ELEMENT WHEREBY SAID THRUST ELEMENT IS EXTENDIBLE UNDER THE BIAS OF SAID BIAS MEANS TO MOVE SAID DOOR INTO SAID OPEN POSITION. 